JP2003129946A - High pressure plunger pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high pressure plunger pump being light in weight, capable of suppressing the damage of members forming a pressure feed passage, reducing kind of parts and manufacturing cost, providing a large degree of freedom in installation, and reducing cost of the whole device, and applicable even when using two common rails. SOLUTION: This high pressure plunger pump has a plurality of pump plungers 5 formed in a pump housing 1, energized by a force of a spring 2, and reciprocating through a cam 4 rotated by an input shaft 3, a pump chamber 6c pressurized by the plungers, and a cylinder head 6 forming the pump chamber. A check valve 11 and a discharge port 12 are provided in the cylinder head and are separate from the pump housing. A pipe collection block 14 is attached to the pump and is provided with an end connection 40 corresponding to the discharge port, a communicating passage 41, and a flow-out port 42. Each end connection and each discharge port are mutually connected per one set of them by a piping member 44.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high pressure plunger pump for fuel injection.

[0002]

2. Description of the Related Art A plurality of plungers are arranged radially on the outer circumference of a cam, and a so-called star-shaped plunger pump that pressurizes and discharges fuel sucked into a fuel pressurizing chamber (pump chamber) formed for each plunger. It has been known. In this type of pump, the fuel pressure feed passage for feeding the high-pressure fuel pressurized in the fuel pressurizing chamber is joined directly into the pump housing, and the fuel is fed from the joined fuel pressure feed passage to the common rail. Is common. However, when a plurality of fuel pressure feed passages are merged into one fuel pressure feed passage in the pump housing, a corner portion is formed at a communicating portion of the fuel pressure feed passage. on the other hand,
In a common rail diesel engine, the fuel may be pressurized up to around 200 MPa during fuel injection. Therefore, if a corner is formed on the inner peripheral wall of the pump housing that forms the fuel pressure feed path, stress concentrates on the corner due to the fuel pressure. However, the corners may be damaged. Furthermore, in order to reduce the size and weight of the engine in order to reduce fuel consumption, it is difficult to reduce the weight of the fuel pump if iron-based materials are used because the strength of the main body is required in the structure that merges the fuel pressure feed path in the pump housing. There is.

In view of this, in Japanese Patent Laid-Open No. 2000-240531, the cylinder head is a separate component from the pump housing, a pressurizing chamber is provided in the cylinder head, and the high pressure fuel from the pressurizing chamber is provided in the cylinder head as a check valve. A discharge port is provided for sending out through. As a result, high pressure was not applied to the pump housing, and the pump housing was made of aluminum to reduce weight. Further, the fuel pressure feeding path for carrying out the high-pressure fuel is connected between the cylinder heads by piping, and the piping from one cylinder head to the common rail is connected to reduce the corner portion of the inner peripheral wall of the fuel pressure feeding path to reduce the high pressure. It is easy to endure.

However, when the cylinder head and the pump housing are separated, the cylinder head and the cylinder head are connected by piping, and the piping from one cylinder head to the common rail is connected, each cylinder head has the same shape. In order to do so, it is necessary to add extra thickness or make a hole to make it common with the cylinder head for the common rail. In addition, there are restrictions on the direction and location of the connection port to the pipe to the common rail, and the mounting of the pressure adjustment valve and detector for common rail pressure. Further, in a V-type engine such as a V6, V8 cylinder or the like, there are two common rails, which makes it difficult to make the cylinder head common.

In view of the above-mentioned problems, an object of the present invention is to provide a lightweight fuel injection pump having features such as suppressing damage to a member forming a fuel pressure passage, while reducing the number of parts. It is to provide a fuel injection pump that reduces manufacturing costs. Another object of the present invention is to provide a high-pressure plunger pump which can be applied to the case where two common rails of a V-type engine such as a V6, V8 cylinder are used and which can reduce the overall cost. Furthermore, it is to increase the installation flexibility.

[0006]

According to the first aspect of the present invention, a plurality of cams, which are respectively formed in the pump housing and are biased by spring force and rotate the input shaft, reciprocate. A star-shaped high-pressure plunger pump having a pump plunger, a pump chamber pressurized by the pump plunger, and a cylinder head forming the pump chamber, wherein the cylinder head reverses high-pressure liquid from the pump chamber. A discharge port for discharging through a valve is provided, and is a separate component from the pump housing, and a collecting tube block is attached to the high-pressure plunger pump, and the collecting tube block is connected to the discharging port. Corresponding connection ports, communication passages that connect the connection ports to each other, and outlets that allow pipe connection from the communication passages to the outside. The has solved the above problems by providing a high-pressure plunger pump, wherein each connection port and each said discharge port is connected by a set by one pipe member, respectively.

In other words, according to the above structure, the fuel pressure feed passages from the respective cylinder heads are connected to each other by piping without communicating with the inside of the pump housing, so that the length of the pump internal pressure feed passage can be shortened and the corner removal work can be performed. It will be easier. In addition, there are few corners that intersect the communication path of the cylinder head, and there are few stress concentration points. In addition, the members that form the fuel passages are made of high-strength iron-based materials, and the components of the pump housing that do not apply pressure are compared to iron-based materials. In the present invention, the cylinder head can be made common by providing the collecting tube separately, while the conventional features such as the weight saving of the pump can be achieved, so that the types of the parts can be further reduced and the cost of the parts can be reduced. It can be reduced. Further, even if the pump main body including the cylinder head remains the same, the connecting port, the outflow port, and the opening hole can be appropriately selected only by changing the collecting pipe block or by selecting each port of the collecting pipe block. Moreover, since the number of ejection ports of the cylinder head is small, it is easy to downsize the cylinder head.

Further, according to the invention of claim 2, since the collecting block has a plurality of the outlets, it can be directly connected to two common rails of a V-type engine such as a V6 or V8 cylinder. Further, in the invention of claim 3, it is used by connecting the outlet port of the collecting pipe block to a common rail.

Further, in the invention of claim 4, since the opening hole is provided in the collecting pipe block so as to be able to be connected to the outside from the communication passage, a valve or a measuring instrument for pressure detection or pressure adjustment of the common rail is provided. Can be easily connected. Although the pipe may be connected from the opening hole to connect to a valve or the like, in the invention of claim 5, since the pressure control valve (safety valve) or the pressure sensor is directly attached to the opening hole, the entire apparatus becomes more compact. .

According to the invention of claim 6, since the collecting block is provided on the side surface of the pump housing, it can be shortened in the longitudinal direction and is suitable for mounting on a V-type engine or the like. on the other hand,
In the invention of claim 7, since the pipe collecting block is provided at the rear of the pump, the pipe collecting block can be integrated with the rear lid of the pump housing. Further, if the respective discharge ports and the respective connection ports are arranged around the axis for the time being, the two pipes can have the same piping member because they have a similar relationship.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a high-pressure plunger pump showing a first embodiment of the present invention, FIG. 2 is an external view, (a) is a front view, and (b) is a left side view. Note that FIG. 1 is a cross section taken along the line AA of FIG. As shown in FIG. 1, a pump housing 1 made of an aluminum alloy, which constitutes the high-pressure plunger pump 51, is biased by spring forces of a plurality of springs 2 and has an input shaft 3.
A pump plunger 5 that reciprocates via a cam 4 that is rotated by is provided. Three pump plungers 5 are arranged in the radial direction in three equal parts around the axis, and each reciprocates in the radial direction. Outermost tip 5a of pump plunger 5
Is slidable in the cylinder hole 6a of the cylinder head 6, and the pump chamber 6 is formed by the tip portion 5a and the cylinder hole 6a.
b is formed. A suction check valve 9 is provided outside the cylinder hole 6a of the cylinder head 6 so that fuel can be supplied to the pump chamber 6b but cannot be discharged. The non-pump chamber side of the suction check valve 9 communicates with the cylinder head 6, the pump housing 1, and the feed fuel passage 8 which communicates with the front lid 20. The front lid 20 is provided with a bearing 31 that supports the front portion of the shaft 3, a seal 32, and a snap ring 33 that fixes the seal, and is fixed to the housing. A bearing 34 for supporting the rear portion of the shaft 3 is provided at the rear portion of the pump housing 1.

The feed fuel passage 8 formed on the outer periphery of the front lid 20 further communicates with the discharge port of the feed pump 19 through a passage (not shown). The feed pump 19 is rotatably connected to the rear end of the shaft 3 and is connected to a fuel tank from an intake port (not shown). Feed pump 1
The rear lid 30 is fixed to the pump housing 1 with bolts 37 also to form the pressure chamber 9 of the pump. The cylinder head 6 is a separate part from the pump housing 1 and is made of an iron-based material. A supply path 10, a check valve 11, and a discharge port 12 which communicate with a pump chamber 6b formed in the cylinder head and extend in the axial direction.
Are sequentially provided in a straight line, and the high-pressure fuel in the pump chamber is discharged from the discharge port 12. Reference numeral 35 is a lid of the intake check valve 9, 36 is a bolt for fixing the cylinder head 6 to the housing, and 38 is a key.

Particularly in the present invention, the discharge ports 12 (1) are respectively provided to the three cylinder heads 6 (6a, 6b, 6c).
2a, 12b, 12c), while a collection tube block 14 made of an iron-based material is fixed to the upper part of the pump housing 1. Rear end of the collecting block 14 (left in FIG. 1) 14
There are three connection ports 40 (40a, 40b, 40c) in a.
Is provided, and each connection port is connected by a communication passage 41. Further, the upper portion 14b of the collecting pipe block 14 is provided with an outlet 42 communicating with the communication passage 41 and connected to the external pipe 43. The external pipe 43 is connected to a common rail (not shown). Each connection port 40a of the collecting block 14,
40b, 40c and the discharge ports 12a, 12 of the cylinder head
b, 12c and the piping member 44 (4
4a, 44b, 44c). An opening hole 45 is formed on the front end (right end in FIG. 1) 14c side of the collecting pipe 14, and a pressure control valve (safety valve) 16 is mounted in this opening hole, and an abnormal pressure is generated in the line of the communication passage. When the fuel oil is generated, the fuel oil is discharged from the pressure control valve 16 through the drain passage 17 in the pump casing.

The operation of such a high-pressure plunger pump will be described. In the figure, the feed pump 19 sucks fuel from the tank by the rotation of the shaft 3 and passes through the discharge port of the feed pump, the feed fuel passage 8, and the suction check valve 9. Fuel is supplied to the pump chamber 6b. On the other hand, the rotation of the shaft 3 causes the cam 4 to reciprocate the pump plunger 5 to perform a pumping action to supply fuel to each pump chamber 6b, and further to supply high-pressure fuel from the pump chamber to the supply passage 10,
The pressure is fed to the discharge port 12 via the check valve 11. The fuel from each discharge port merges into the communication passage 41 through each pipe member 44 and each connection port 40, and high-pressure fuel oil is supplied from the outlet port 42 through the external pipe 43 to the common rail.

FIG. 3 is a left side view showing a second embodiment of the present invention. This is an example in which the collecting tube block is provided at the rear end of the pump. The description of the same parts as those in the first embodiment described above will be omitted, and some parts will be denoted by the same reference numerals.
As shown in FIG. 3, in the second embodiment, as described above, the discharge port 12 of the cylinder head 6 is opened toward the rear of the pump, while the material of the rear lid is an iron-based material, It was integrated with the block. Connection ports 40 are provided on the rear end surface 14a of the collecting tube 14 'in three equal parts around the axis, and the discharge port 12 and the connection port 40 are connected by a U-shaped bent pipe member 44. According to this, the same member can be used for the piping member 44. Further, the size can be reduced in the radial direction. The outlet 42 and the external pipe 43 connected to the common rail are provided in the left oblique direction. The pressure control valve 16 is not shown.

FIG. 4 is a left side view showing a third embodiment of the present invention. This is an example in which a collecting block is provided on the upper part of the pump and is connected to two common rails.
The description of the same parts as those of the first and second embodiments described above will be omitted, and some of them will be given the same reference numerals. As shown in FIG. 4, in the third embodiment, compared to the first embodiment,
The cross-sectional shape of the collecting tube is made into a substantially four-lobed shape, and the rear end 14
Two outlets 42a and 42b are provided in a, and the front end (rear end 1
Two openings 45a and 45b are provided on the side opposite to 4a). FIG. 5 shows a piping diagram when the high-pressure plunger pump having such a structure is applied to a V6 engine. As shown in FIG. 5, the common pipes 1 are attached to the common rails 25a and 25b.
4 ″ from the outlets 42a, 42b to the piping members 43a, 43
Connected at b. One opening 4 of the collecting tube block 14 "
A pressure sensor 24 is attached to 5a, and the discharge pressure is measured. The pressure control valve 16 described above is attached to the other opening 45b. Reference numeral 26 is a fuel injection valve connected to the common rail.

Conventionally, as shown in FIG. 6, a block 53 is provided between the fuel pump 52 and the common rails 25a and 25b, and connected to the common rail with piping members 54a and 54b.
A pressure control valve (safety valve) 16 and a pressure sensor 24 are installed in the block 53, and a return path of the pressure control valve 16 is returned to the tank 56 by a piping member 55. In the present invention, since the return path of the pressure control valve 26 is returned to the inside of the pump housing, the piping member 55 becomes unnecessary. In the above-described embodiment, the case where the number of pump plungers is three has been described, but the same applies to the case where the number of pump plungers is two or four. When the number of pump plungers is two, it is preferable that the collecting tube block is attached to the side surface of the pump housing. When the number of pump plungers is four or more, the collecting block may be provided on the rear side of the pump housing, which saves space.

[0018]

According to the first aspect of the present invention, the fuel pressure feed passages from the respective cylinder heads are connected to each other by pipes without being communicated with each other within the pump housing, and a collecting block is separately provided, so that all cylinder heads are made common. As a result, it is possible to reduce the number of types of parts and the manufacturing cost while providing a lightweight fuel injection pump having features such as suppressing damage to the members forming the fuel pressure feeding passage. Further, by simply changing the collecting tube block, or by appropriately selecting the connecting port, the outlet port, and the opening hole of the collecting block, the discharge port of the cylinder head can be reduced, and the cylinder head can be easily downsized.
It has a wide range of applications and has a high degree of freedom in installation.

Further, in the invention of claim 2 or 3,
There are two outlets of the collecting block, and 2 of V type engine
Can be directly connected to the book's common rail, reducing the overall cost. Further, in the invention of claim 4, the pressure detector and the pressure adjusting valve are connected to the opening hole of the collecting tube to make the entire apparatus more compact and increase the degree of freedom in installation.

In the invention of claim 6, the collecting tube block is attached to the side surface of the pump housing so that it can be shortened in the longitudinal direction. On the other hand, in the invention of claim 7, it is attached to the rear of the pump so that a small number of cylinder heads can be used. On the other hand, since the collecting block can be arranged according to various mounting conditions, a high-pressure plunger pump having a wide range of applications can be provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a high pressure plunger pump showing a first embodiment of the present invention.

FIG. 2 is an external view of a high-pressure plunger pump showing the first embodiment of the present invention, (a) is a front view and (b) is a left side view.

FIG. 3 is a left side view of a high-pressure plunger pump showing a second embodiment of the present invention.

FIG. 4 is a left side view of a high-pressure plunger pump showing a third embodiment of the present invention.

FIG. 5 is a piping system diagram relating to a common rail for a V6 type engine using a high-pressure plunger pump according to a third embodiment of the present invention.

FIG. 6 is a piping system diagram relating to a common rail for a V6 type engine using a conventional plunger pump.

[Explanation of symbols]

1 Pump housing 2 spring 3 input shaft 4 cams 5 Pump plunger 6 cylinder head 6c pump room 8 feed fuel passage 9 Inhalation check valve 10 Discharge port 11 Check valve 12, 12a, 12b, 12c Discharge port 14, 14 ', 14 "collecting block 16 Pressure control valve (safety valve) 24 Pressure sensor 25, 25a, 25b common rail 40, 40a, 40b, 40c Connection port 41 passage 42 Outlet 44, 44a, 44b, 44c Piping member 45, 45a, 45b Open hole 51 High pressure plunger pump.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02M 59/44 F02M 59/44 V 59/46 A 59/46 Y F04B 1/04 F04B 1/047 21 / 00 K 1/053 53/16 (72) Inventor Yasushi Shimoguchi 1-1-1 Fujikoshi Honcho, Toyama City, Toyama Prefecture Stock company Fujikoshinai F-term (reference) 3G066 AB02 AC01 AC09 AD12 BA48 BA61 BA63 BA67 CA00 CA01S CA08 CA09 CB01 CB07T CB12 CD04 CD15 CE02 CE34 DC18 3H070 AA02 BB03 BB17 BB25 CC34 CC35 DD01 DD91 DD96 3H071 AA07 BB01 CC33 CC34 DD31

Claims (7)

[Claims] 1. A pump plunger that is reciprocated through a cam that is formed in each of the pump housing and that is biased by a spring force and that rotates an input shaft; a pump chamber that pressurizes the pump plunger; A star-shaped high-pressure plunger pump having a cylinder head forming a pump chamber, wherein the cylinder head is provided with a discharge port for discharging high-pressure liquid from the pump chamber via a check valve, and It is a separate component from the pump housing, and further, a collecting tube block is attached to the high-pressure plunger pump, and the collecting tube block has connection ports respectively corresponding to the discharge ports and a communication port communicating the connection ports with each other. A passage and an outflow port that can be connected to the outside from the communication passage by piping, and each of the connection port and each of the discharge ports respectively. A high-pressure plunger pump, characterized in that they are connected one by one by piping members. 2. The high-pressure plunger pump according to claim 1, wherein the collecting pipe block has a plurality of the outlets. 3. The high-pressure plunger pump according to claim 1, wherein the outlet of the collecting pipe block is connected to a common rail. 4. The high-pressure plunger pump according to claim 1, wherein the collecting pipe block has an opening hole that can be connected to the outside from the communication passage. 5. The high-pressure plunger pump according to claim 4, wherein a pressure control valve (safety valve) or a pressure sensor is attached to the opening hole. 6. The high-pressure plunger pump according to claim 1, wherein the collecting tube block is provided on a side surface of the pump housing. 7. The high-pressure plunger pump according to claim 1, wherein the collecting tube block is provided at the rear of the pump.